Brush-holder for electrical machines.



No. 753,866. PATENTED MAR; 8, 1904.

W. H. FOOT. BRUSH HOLDER FOR ELECTRICAL MACHINES.

APPLICATION FILED JUNE 24, 1903.

N0 MODEL. 2 SHEETSSHEET 1.

WITNESSES: INVENTOR No. 753,866 .PATENTED MAR. 8, 1904.

W. H. FOOT.

BRUSH HOLDER FOR ELECTRICAL MACHINES.

APPLICATION FILED JUNE 24, 1903.

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UNITED. STATES Patented March 8, 1904.

PATENT OFFICE.

-WILLIAM H. FOOT, OF WVILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC 8: MANUFACTURING COMPANY, A COR PORATION OF PENNSYLVANIA.

BRUSH-HOLDER FOR ELECTRICAL MACHINES.

SPECIFICATION forming part of Letters Patent N0. 753,866, dated March 8, 1904. Application filed June 24, 1903. Serial No. 162,908. (No model.)

To all whom it may concern.-

Be it known that I, WILLIAM H. FooT, a subject of the King of Great Britain, residing at Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Brush-Holders for Electrical Machines, of which the following is a specification. I

My invention relates to brush-holders for electrical machines; and it has for its object to providea brush-holder comprising a plurality of individually-actuated brushes of such construction that its position on the rocker-arm which carries it may be easily and quickly reversed when it is desired to reverse the direction of rotation of the armature.

It is often desirable in the operation of electrical machines to reverse the direction of rotation of the armature. This necessitates reversal of the positions of the brush-holders on the rocker-arms which support them. On large machines it is a common practice to employ a plurality of brushes instead of one having the same aggregate area, because it is difiicult to keep the whole area of a single carbon in contact with the commutator-cylinder. The holders for the individual carbons are often castv in one piece for the purpose of reducing the number of parts and of obtaining a simple rigid bracket, and good contact is maintained between the carbons and the commutator-cylinder by means of springs which press against the outer endsof the said carbons. Since it is desirable to efiect individual adjustment of pressure upon each of the carbone, a separate spring and means for varying its tension is provided for each of'them.

My invention is illustrated in the accompanying drawings, in which Figure 1 is a transverse sectional view of a brush-holder constructed inaccordance therewith. Fig. 2 is a longitudinal sectional view taken on line II II of Fig. 1, a portion of the commutator-cylinder being shown in side elevation.

The rocker-arm 1 is provided with a longitudinal projection 2 on each side thereof, the one or the other of which fits into a corresponding recess in the brush-holder bracket 3, substantially as shown. The bracket 3 is secured to the rocker arm by means of tap bolts 41, which are easily removed and replaced when reversing the brush-holder, such reversal being effected by transferring the bracket from one side to the other of the rocker-arm, according to the direction of rotation of the commutator-cylinder 5.

A suitable pressure is maintained upon the brushes 6 by means of spiral springs 7, the free ends of which rest upon the outer ends of the corresponding brushes. The other end of each of the springs 7 is secured in a slot 8 in the hub 9 of a corresponding worm-wheel 10. The worm-wheels 10 are severally actuated by worms 11 on the ends of spindles 12 in order to vary the pressure exerted by the corresponding springs 7. All of the worm-wheels 10 except the one at the extreme right, as shown in Fig. 2, are independently mounted on a shaft 13, about which they are free to rotate in order that they may be individually adjusted.

The end worm-wheel 10 is secured to the shaft 13 by means of a pin 14, and a wheel 15 of the same form and dimensions, except that it has no laterally-extended hub, is secured to the other end of the shaft by a similar pin 16. This construction allows of the adjustment of the spring 7 which is attached to the hub of the end wheel 10 from either end of the brushholder bracket 3, and in order to facilitate such adjustment the end spindle 12 is made interchangeably useful in connection with either of worm-wheels 10 and 15. The removal of a cotter-pin 17 and the head 18, which it holds in position, permits of the ready removal of the spindle 12 from its position at either end of the brush-holder bracket.

The end spindle 12 is always placed in the end of the bracket which is farthest from the armature in order that the tension of the end spring 7 may be adjusted without danger to the attendant, and it is therefore evident that said spindle must be changed from one end of the bracket to the other whenever the brushholder is reversed in position on its rockerarm and that the construction herein described greatly facilitates such change.

It would of course be feasible to utilize a single detachable worm-spindle for actuating all of the worm-wheels or to employ a wormspindle for each of the worm-wheels, including wheel 15, and I therefore desire that my invention be construed broadly enough to cover such variations from what is hereinbefore specifically set forth.

The remaining parts of the brush-holder are well known in the art and need not here be described, my invention pertaining only to the adjustment of the springs when reversing the direction of rotation of the machine and the consequent reversal of the brush holder bracket on its rocker-arm.

It is evident that I have provided a means whereby this result may be accomplished easily and expeditiously by disturbing a minimum number of parts, and I do not wish my invention limited to any particular number of individually-actuated brushes or to any specific means for applying pressure to said brushes.

It will be further understood that my invention is not limited to the employment of brushes of any specific form or material, eX- cept as limitations may be imposed by the particular service to be performed in any given case.

I claim as my invention 1. In a brush-holder having a plurality of brushes, the combination with a plurality of springs, of a rotatable shaft having adjusting means for one of the end springs fastened to its respective ends, and separate adjusting means for each of the other springs mounted upon the shaft to turn independently thereof.

2. In a brush-holder having a plurality of brushes, the combination with a plurality of springs acting independently upon the several brushes, of a rotatable shaft having adjusting means for one of the end springs fastened to its respective ends and separate adjusting means for each of the other springs rotatably mounted upon the shaft.

8. In a brush-holder having a plurality of brushes, the combination with a plurality of springs bearing severally upon the brushes, of

a rotatable shaft, adjusting-gears for said springs each of which has one of its members mounted upon said shaft, means for fastening each of said gear members to its spring, means for fastening one of said members to the shaft and a supplemental gear member that is attached only to the shaft.

f. In a brush-holder having a plurality of brushes, the combination with a plurality of springs bearing severally upon the brushes, of a rotatable shaft, a worm-wheel fastened to one end of the shaft and the corresponding spring, a worm-wheel fastened to the other end of the shaft, a detachable worm-spindle for engagement with either of said wormwheels, a plurality of worm-wheels rotatably mounted upon said shaft and severally attached to the intermediate springs, and wormspindles engaging the respective Wormwheels.

5. In a brush-holder having a plurality of brushes, the combination with a shaft having gear members fastened to its ends and intermediate gear members rotatably mounted thereon, of springs respectively attached to the intermediate gear members and one of the end members and bearing upon the respective brushes, manually-operated gear members respectively meshing with said intermediate members and a detachable, manuallyoperated gear member adapted to mesh with either of said end members.

6. The combination with a rocker-arm having a longitudinal projection on each side thereof, a brush-holder having a longitudinal recess in one side and means for clamping the holderagainst either side of the rocker-arm with one of said projections in its recess, of a set of brushes seated side by side in said holder, a set of independent springs for said brushes, means for adjusting one of the end springs from either end of the holder and independent means for adjusting each of the other springs.

7. The combination with a rocker-arm, a brush-holder and means for detachably clamping said holder to either side of said arm, of a set of brushes supported side by side in said holder, a set of springs for said brushes, means for adjusting one of the end springs from either end of the holder and independent means for adjusting each of the other springs.

8. The combination with a rocker-arm, a

brush-holder and means for removably cl-amping said holder to either side of said arm, of a set of brushes supported independently in said holder, a set of springs for said brushes, independent adjusting means for each of said springs, said means for one of the end springs comprising arotatable shaft and an actuating device at each end thereof.

In testimony whereof I have hereunto subscribed my name this 12th day of June, 1903.

WILLIAM H. FOOT. Witnesses:

J. M. HIGGINBOTHAM, BIRNEY HINES. 

